Fix heading for group issue boards
What does this MR do?
Remove -level
from group issue boards heading in docs.
Relevant https://gitlab.com/gitlab-com/www-gitlab-com/issues/1663
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
Remove -level
from group issue boards heading in docs.
Relevant https://gitlab.com/gitlab-com/www-gitlab-com/issues/1663